Paul Parry from Bad Dog Designs took a 1930s Vickers combined voltmeter and ammeter, refurbished it, added the Nixie tubes and then added a Raspberry Pi which translated the data coming in from his solar panels into something usable by the tubes. It’s a great project and is as retro as you can get. Read more and see more photos on his website.
The Raspberry Pi Foundation today has welcomed on-board two new recruits: Oliver Quinlan (as a Research Manager) and Helen Drury (as Events and Outreach Manager). These two individuals, both with Nesta backgrounds are sure to make valuable additions to the team.
In addition to these new appointments, they are also recruiting for the following positions:
So, if you think you’ve got what it takes to fill these roles, click the links above to get more details about the jobs and to apply!
Dan Aldred has done a lovely implementation of the classic game Rock-Paper-Scissors-Lizard-Spock using the SenseHAT. The program is written in Python and is available on Github and you can see a video of it in action below:
On February 27th and 28th, 2016 at the Computer History Museum in Mountain View, CA, the very first Picademy USA will be launched. This is a fantastic opportunity for American educators to get taught how to use the Raspberry Pi, with particularly emphasis on classroom usage, and shouldn’t be missed. To apply, you must be a professional educator. The application form can be found here.
Exciting news for the Raspberry Pi Community! The Foundation will once again be holding a two-day Big Birthday Weekend event in Cambridge. The event, which will take place on 5th and 6th March will celebrate the 4th birthday of the little single board computer and will include talks, workshops, show and tell and a Marketplace. Of course, there will be plenty of people from Raspberry Pi at the event to talk to and lots of community folks will also be attendance – it’s a great event to be a part of! The weekend will be held at the University of Cambridge Computer Lab (where last year’s Birthday Weekend and, of course, Pi Wars were held). The event runs from 10am-5pm both days and there is an early-evening party on the Saturday.
Myself and Tim Richardson have, once again, been asked to help organise it, so expect to hear a lot from us about the event as preparations continue.
Tickets are available here. They are £5 per day for adults, free for those 16 and under and tickets for the party are also £5 (for everybody).
When you’re running your Raspberry Pi headless, one of the first things you should concern yourself with is how to shut it down safely. Shutting it down by simply pulling the power out can result in a corrupt SD card or damaged files. If you had it connected to a network, you could of course just SSH into it and issue the ‘halt’ command. However, what if you couldn’t connect to it? Or what if you just wanted a way to simply and easily shut it down without touching a keyboard at all?
Here’s where Adafruit steps in and gives us a simple script that will monitor a GPIO pin and shut down if it detects a change in state. What use is that? Well, it means you just simply need to connect two pins on the GPIO together with a paper clip (or anything conductive) to issue the halt command. I’ve taken the Adafruit tutorial and some other guides online and put together the following instructions.
Please note: the current version of the software provided by Adafruit takes a second parameter – this is how long you need to “hold” the connection in order to trigger the shutdown. For consistency with Adafruit, I’ve made this “hold time” 3000 milliseconds (3 seconds).
First of all, you will need a Pi with Git installed on it.
sudo apt-get install git
Next, you download the script from Adafruit’s Github:
git clone https://github.com/adafruit/Adafruit-GPIO-Halt
If this doesn’t work, try:
git clone git://github.com/adafruit/Adafruit-GPIO-Halt
An aside: The script is written in C, so is able to be modified if you want to, say, light up an LED when the halt command is issued. You could re-write it as a Python program, of course, which might make it easier for some to adapt.
Change into the new directory, compile and install:
cd Adafruit-GPIO-Halt make sudo make install
This installs the script to /usr/local/bin/gpio-halt. You then need to run it as a service.
In the following sections, if you’re using an older Pi with a 26-pin GPIO header, use GPIO pin 7 instead of 21.
If you’re running Raspbian Jessie, you will need to do it via systemd:
sudo nano /lib/systemd/system/gpio-halt.service
This will create a file and open it. The following is the contents of that file:
[Unit] Description=Short pins 21 and ground to shutdown the Pi After=multi-user.target [Service] Type=idle ExecStart=/usr/local/bin/gpio-halt 21 3000 & [Install] WantedBy=multi-user.target
Then, make the script executable by the right users:
sudo chmod 644 /lib/systemd/system/gpio-halt.service
Then, tell systemd to use the script:
sudo systemctl daemon-reload sudo systemctl enable gpio-halt.service
And reboot your Pi
sudo reboot
When the Pi comes back up, you can check the status of the service by doing:
sudo systemctl status gpio-halt.service
If you’re running the older Raspbian Wheezy, you will need to do it via rc.local:
sudo nano /etc/rc.local
Before ‘exit 0’, add the line:
/usr/local/bin/gpio-halt 21 3000 &
Now reboot your Pi:
sudo reboot
Take a paper clip (or other conductive object) and touch the last two vertical GPIO pins at the same time and hold for at least 3 seconds. If you’re using a 26-pin Pi, it will be GND and GPIO7. If you’re using a 40-pin Pi, it will be GND and GPIO21. See the diagram below. The first time you do this, it might be worth having a monitor connected so that you can see it happening. Wait about 15 seconds for the halt procedure to complete and then unplug your Pi safely.
Thanks to Alex Eames for spotting the Adafruit shutdown script. Thanks to Adafruit, obviously. Thanks to Matt Hawkins for the systemd instructions. Thanks to commenter Bartwick for noticing that my instructions were out-of-date.
